1. Field of the Invention
The subject invention relates to edging structures and, more specifically, to edging elements for playing fields and sports installations and for methods of making such edging elements.
2. Information Disclosure Statement
The following disclosure statement is made pursuant to the duty of disclosure imposed by law and formulated in 37 CFR 1.56(a). No representation is hereby made that information thus disclosed in fact constitutes prior art, inasmuch as 37 CFR 1.56(a) relies on a materiality concept which depends on uncertain and inevitably subjective elements of substantial likelihood and reasonableness and inasmuch as a growing attitude appears to require citation of material which might lead to a discovery of pertinent material though not necessarily being of itself pertinent. Also, the following comments contain conclusions and observations which have only been drawn or become apparent after conception of the subject invention or which contrast the subject invention or its merits against the background of developments which may be subsequent in time or priority.
German DE-U No. 7 030 096 describes a cover for borders consisting of a molding shaped body of rubber or synthetic material whereby its cross-section increasingly thickens towards the pit. In order to mount this body to the concrete plate it is provided with two dove-tail shaped extensions which provide the required stability in the hardened concrete. In order to improve the elasticity of this body, it is provided with several borings of different diameters arranged in longitudinal direction. With such covers it was shown that the cohesion/holding strength of the two extensions in the concrete was not as great as was expected and that the extensions can detach due to impacts such as striking shots in shotput activities or that the concrete can break away. An improvement with regard to this disadvantage was to be effected by the German DE-C No. 2 350 099. Hereby the rubber profile was to be placed onto the concrete plate only, whereby a dove-tail shaped extension was provided on the concrete part and correspondingly, the flange at the rubber profile. Although an improvement resulted with regard to the breaking out of concrete, no improvement with regard to the mounting was effected.
Another mounting system was provided in German DE-U No. 7 410 473 which is also shown in the German DE-U No. 7 827 601. The rubber profile is provided with a widening ledge that was embedded into the wet concrete. Although this ledge can form a good mounting in massive concrete bodies such as drainage channels, there are reasonable doubts regarding its usefulness when such a widening ledge is embedded in the frontal area of a concrete plate, because the concrete can easily break away in the fringe areas next to this ledge.
British Patent specification No. 650,674, by G. S. Marston, discloses marking means for tennis courts, roadways and the like, being essentially T-shaped or H-shaped in cross-section, and having slots for providing increased holding by the material of the court. French Pat. No. 2 436 329 (79 22811) by Harald Mortsiefer et al, discloses hollow edgings profiles for sports installations, in which a thickened bead of a longitudinally extending and projecting strip is anchored in concrete. U.S. Pat. No. 1,896,641, by J. R. O'Brien, discloses road markers in which a web or depending portion has openings therethrough and anchors inserted therein for embedment in the pavement. Reference may also be had to my earlier U.S. Pat. No. 4,336,932, issued June 29, 1982 to the common assignee hereof, for Edging for the Track Inside of a Sports Installation, and to the U.S. and foreign patent documents cited therein.